Machine for digging tunnels



I'Fheet l 2 she j B. A. CHUBBUCK Filed March 12..` 1921- Der.;` 6, 1927.

MACHINE FOR DIGGING'TUNNELS .llllllllltrxll Mm/g.

Dec. 6, 1927.

CHUBBUCK MACHINE FOR DIGGI'NG TUNNELS 2 Sheets- Sheet 2 Filed March 12.1921 nasales nee. e, isa?. l'

yUNE

BUI-rr A. crrunisncmor 'MCDONALQ PnNNsYLvANrA.

sa ,raufc Application filed March 12, 192.1. Serial No. 451,861.

This invention relates to machines for cutt-ing'tunnels, digging coal,removing the vertical surface from ledges of rock, etc. The object ofthe invent-ion is to improve the mechanism of machines adapted to thepurposes above referred to, and operatingV by means of a pluralityofreciprocating cutting blades driven byk compressed air, steam, orother fluid pressure. Additional purposes and advantages of theinvention a part of the machine, comprising a pair ofA tool-drivingcylinders, partly in horizontal section; Fig. 3 is a partial plan anddiagram 'i showing a modification; Fig. l is a section on line l-ll ofFig. 3; and'Fig. 5 is a partial elevation in enlarged form showing one'of the pressure regulating valves and its operative connections. A

In cutting tunnels, entry Vways in coal veins, and the like, it has longbeen desired to haveV a machine which will remove the surface of thematerial through which the cut is being made over the entireend of theopening that is to be made. In order to do this without blasting, it isnecessary to remove thel material in comparatively small pieces, thatisto say, by chipping it off with hammer like blows as opposed tounder-cutting vand* knocking down in large masses. For this purpose,various machines have been devised, having a plurality of cuttingbladesl or tools which are driven against the surfaceof material to becut, the blades being nioveL frcm place to place, so as not to dig holesin the material, but, on the contrary to chip it ofi in comparativelysmall portions. It is to this class of machines that the presentinvention relates, and y specifically it relates to such machines.ydriven by fluid The invention is particularly concerned with the meansfor supplying, controlling and regulating the pressure ofthe fluiddriving means to secure' uniform and certain action of the machanism,and to cushion the str-oke of the cutting tools at both ends of theirmovement by trapped fluid. The control of the fluid for driving,retracting, cushioning and generallyoperatingthe cutting blades is averydelicate Vmatter,and l the successful operation of such a" machine 1y .depends very'largely upon the details and 'l efficiency of thecontrol mechanism. z

Referring to the` drawings, the machine V() to which thisl inventionhasbeen appliedcmprises a suitablebase or frame, which rides bymeans ofsuitable rollers laupon a track l. fioor. A rack member 2 isrigidwiththe track and furnishes' means forl propelling the machine backand forth. The frame comprises supporting side members '3 `which carryat their top a shaft 4, 'to which the battery of cutting Vmechanism ispivotally attached by means of a base plate 4a. A seg! This track isylaid directly on the mental gear member 5 is rigidly attached toV fthebottom of the -base plate 4f* carrying the battery ofcuttingcylinders to be later described. The curved portion of this segment hasgear teeth 6, meshing with a small` gearor pinion?, which isdriven. bymeans ofa shaft- 8, an intermediate gear 9,'shaft v 10, sprocket 11,chain 12,'sprockets-13 and 14, chain 15 and sprocket 16. vThe shaft 10is driven through thepositive connections vjust're'f'erred to=from themotor shaft 17. 'A transmission and reversing' gearmechanism,` such asthat used in automobiles, connects 1 shaft 10 Vto a small gear lyingldirectly behind the sprocket 11a, which meshes with the large gear 9anddrives it in either direction, as will be understood. yTherefore, by

driving through the various connections f above referred to, thev fixedpinion 7-when rotated will'drive segment 5, and so raise or lower thecutting tools as will be obvious.

`Shaft 10 carries a sprocket 11a connected by a chain 11b to al sprocket20a on shaft 20h, i i

which is connected through a train of gears including a lreversingmechanism to pinion i 2Oc on shaft 20d. The pinion 20cemeshes` with rack2, which is immovable. wWhen the pinion 2()c is driven, the machine iscaused to travel forward or back, upon the track Vmembers 1, and thismechanism is usedto V bring the machine into operative contact with thewall that is to be cut, and to vwithdraw the machine for repairs,removal, etc. My invention does not reside inl the frame, supporting,niiachine. A control lever 22 is connected tothe driving `segmentgear'mechanism by means of a connectingbar 26 and a lever arm 2'?ypivoted at.k 28, as illustrated. The

or forward-driving part of .the

All.

means of the cutting blades, and such means fj will now be described.

shows such apair of cutting` members, and, any additional units would besimply duph-A cates of the pair illustrated.

Referring tov F1g.`2. the cutting mechanism comprises a .crank shaftoperating in a casing l51, and having attached thereto connecting rods53 and 511, exactly as in the case of an ordinary multiple cylinderVexplosive engine. It will be understood that the crank shaft 50 extendsthrough other crankshaft casings 51 similar to that illustrated, andthat itis driven at one or both ends by suitable mechanism for rotatingit upon its longitudinal axis.

The connecting rods have suitable bearing members 55 engaging the crankshaft, and at their other ends are attached, by means of connecting pins56, to pistons 57 and 58, respectively, which are positioned incylinders59 and 60, respectively'. These pistons have the ordinarypiston rings forming a fluid-tight contact withv the interior wallsofthe cylindersjust as in the ordinary explosive -engine construction.The forward ends of the cylinders are closed by a boltedon terminalplate member 61, having central openings r62 leading therethrough.Bolted on to the exterior of the plate 61A are cast" ings 63, to whichare flexibly attached castings 64, the two castings together formingl apassage `65, leading from the opening 62 to an opening 66 formed in themiddle portion of a plate 67 bolted on to the casting member 64, andVforming an end wall of a I cylinder 68, bolted thereto. The interior ofcylinder 68 toward its forward end is reduced toV a slightly-smallerbore 68, and a` ofthe cylinder is further restricted by a transitionportion 71, beyond which the cylinder extends in a smaller bore, orneel; portion 72. -At its outer end, `the cylinder is closed by abearing member 73, clamped into the ends of the cylinder by screws`'741. Inside the large bore of the cylinder a piston member 80 ismounted, and makes close fit with the walls thereof by means of theordinary piston rings.V This piston member carries cn its forward sidean extension in the'form of a hollow shaft 81 extending out through thebearingl', and carryingv on its external end one of thccutting tools ofthe machi-ne. i

This cutting tool comprises a body portion 90, having a rearwardlyextending portion 91, which is bored out to receive the conical terminalhead 92 ofthe shaft 81.. This ferrule-lilre portion 911 ijs-held on theend'of the shaft 92 by means of a taper pin 943 extend-V ingtherethrough, or by any other suitable means. Attached to the. forwardend of the body 90 are cutting chisels 941 formed with cutting edges 95.These latter areadapted to strike and chip off the surface of the wallbeing cut away. They are removable, being clamped in position by a platemember 96, Y

cooperating 'with a lower integral port-ion 97 of the booy 90 and bolts98extending between these two members and clamping them together, thecutting chisels being carried between.

A special wall `and bearing member seats in the restricted second bore68a of the cylinder, between the collar 70 and the `restricting portion71, and furnishes an air-tight bearing and end wall for that portion ofthe cylinder beyond the piston 80.V This inember is built up of a seriesof removable discs 100, which are'bolted together, making up what issubstantially/a solid block withl annular internal recesses forreceiving piston rings. A bolt 102 extends through theremovable ringsand holds them securely together. vBetween the discs are piston rings103. These` are normally somewhat smaller than the shaft 81 and,therefore, bear resiliently against that i'neii'iber thouglv held inposition in the exterior bearing inembers; Such 'a constructionfurnishes an eiiicient lock against escape of pressure from the chamber104 formed between this packing member just above described and theexterior head of the piston 80.

The piston 80, which is integral with the shaft 81, has an extensionSO,which is in effect an enlargement of the shaft 81, eis tending into the`chamber 101. This enlarged extension is circular, and carries aremovable sleeve member 105, which is designed to fit into the circularopening formed by the collar member 70. On the other side of the piston80 another extension is formed by means ofa plug 106, fastened into thebore and forming an extension ofV volf piece's thereof. ward stroke,which is illustrated atithe y'top aredriven forward to thepositionillustrated by piston 57 the air in chambers 115 is driven throughthe'passages 65 .and into ithe chambers 109, and ofcourse drives themovable pistons 80 forward. These, in turn carry the shafts'l,andconsequently the cutting` blades, forward with a quick stroke,

ofF ig. 2 by 'the piston v57, the pistons 'are withdrawn, thereby*exhausting lair from thechamber 109and relieving'fthe pressure on the'rear of lpistons 80, which are immediately withdrawn, or lforced'ba'ek,by reason of the pressure` in ,chambers 1011. v By this lobvious fromthe Construction.

means', 'the "piston-s 80,'and the shafts 81 and the cutting`to`ols kf90carriedf thereby, are

driven 'rapidly lforwardtmd back by compressed'air. `Nopositivedrivingof the cut ting tool is employed, and this 'is highly important, sinceif such tools were forced ositivel forward a certain distance and` werevto strike substanceswhich.would not give away, isomethingwould havetobreak, as willbe obvious.

vThe travel ofthe cutting tools forward and back is positivelycushioi'icd at each end ofthe stroke by an airdash pot, as will be i'ForV`example, lool'ring at Ythe cylinder `-681i`n`section in Fig. 2, thecutting tool is shown in position nearing the 'end ofits rearwardstroke. Further travel backward ofthe piston 80 will bring the extension107 into the bore of passage 66. The sleeve member 107 is made to -fitaccurately into this bore, Iand consequently, further travel past theposition illustrated willresult in cutting oft all escape of air fromthe chamber 109, and the trapped air will be'compressed, ifurnishing acushion which will absolutely preventfthe vpiston from traveling as farasthe end ofthe cylinder.

On the otherhand, atthe forward end of the stroke, the "travel of thecuttingtool isl limited by an fair cushion formed when the forwardextension comes to the bore4 formed by the collar member 70, asillustratedA in Fig. -1. Any further forward travel beyond the positionshownin Fig. 1

causes the'contact of 'collar 70 and piston member105 to shut o ifvescape of air from the space 150, which lies between the collar 70 andthe forward side ofthe piston 80.

, .The members 105 and.107 are made of a metal and informs lwhich willgive avery accurate'iit. AThey maybe removed for repair or renewal whenworn so that leakage ofV igen-1,6m

The chambers l104 in each `pair ofperat-k ing cylindersarefreelyconnected, throughl thepipes 110. It will be "observed from the Varrangement of the crank Yshaft that the'pis tons 57 and 58arereeiprocated in opposite directions. That is to say, one is alwaystraveling Vforward when the other is travell hind 'the vpistons"80S ifshighly important. In

fact, the success of the machine largely'de-- pends upon this. 1f thisvpressui-ie becomes reduced throughleakage, or for "any 'reason thispressure is not high enough, the l: pistoii 80 and the cutting` toolwill bewithdrawn too far, and ktoo quickly, by 'mea-ns of the pressurein chambers 104, vlandlikewise they vwill not be drivenYforward'sutiiciently far,

or sufficiently quick to secureV tlie desired cutting action.

sure between the pistons 57, 58, and V80, and particularly in vorder toimmediatelycorr'ect such condition when it eXis'ts,"the'adjustingmembers 125, 126, and 131 above referred 'to are provided. By means of`these members, or equivalent construction, should the pressure betweenthe v`two pistonsfallbelow 'the' required amount, with a consequentretrac tion of thecutting member beyondfthepoint where't is intended tocome, the setscrew 131 will strike the terminal 1'29o`f the adjust-ingrod 126. lThis, in turn, willmove the arm against` resistanceofspring-l/i and will momentarily open lthe valve Y114, permitting aslight additional supply of fluid to the ,space between'thetwo pistons.This feature isvery important 'andhighly i etcient. VIt insures `that anadjustment of air press-ure 4will take place on theY very stroke that itbecomes necessary, and prevents any undue strain upon 'the machine, orimpairment of the cutting` eiiiciency that would result from a depletedpressure between the two operating pistons.l

Then the battery of'cutting cylinders is inclined downwardly, as forexample when it is cutting from a wall near .its base, that is to say,nearly down tothe level of the *track upon which the machine is mounted,

the weight of the tool-carrying piston will naturally tend to causethose members Vto move forward more quickly, andto move farther, thanwould be the case where 'the y machine is operating in a horizontal`lposi- In order to avoid thiscon dition, and lto 'maintain the desir-edprese loi) ' tomatically vary the tion such as that illustrated inthedrawings. And when the toolsare working above the level position thereverse is true. In order to take care of these conditions, and tosecure the proper cushioning and driving of the pistons in bothdirections and under varying angles-of inclination, and to vsecure theproper quick rebound of the pistons on the return stroke, it may bedesirable to provide means for increasing or decreasing the airpressurein chambers 10a. This I can do' by inea-ns of the pressure regulatingvalves 113, connecting tol those valves an arrangement similar to thatabove described in 'connection with the valve 114. That is to say, meansmay be provided to momentarily open the pressure-regulating valve 113,said means being operated byforward travel of the tool-carrying pistonspast a certain predetermined point. This is not illustrated in thedrawings, since the construction is substantially the same, onlyreversed, as that al ready illustrated in connection with lvalve 114. OrI may use a pressure control valve 113a of astandard construction thatwill aupres-sure as the angle of inclination changes. It will beobserved that in the construction described herein all of the partsconstituting the cylinderfor driving the cutting tools are boltedtogether forming Vin effectan iiitegral structure. It will also beobserved that all of the bores incident to this toolcarrying cylinderare concentric, and in series so that the casting forming the operatingcylinder may be machinedv out with one setting in a suitable boringapparatus. This is important since it is absolutely necessary ting endof the machine, and to convey the trated or claimed.

broken materia-l to the back of the machine,

or to dump it into suitable cars for carrying it away.v Such apparatusis not a part of this invention, and is therefore not illus- Onesuccessful way for doing this comprises an ordinary screw conveyorVextending across the front of the machine at the floor line. This willgather the material and transfer it to a second conveyor Vmay be madeinl some `of the parts illustratedv and described, without departingfrom the principles of the invention disclosed,` Many i in the rearpiston wall.

additiongl advantages and functionsofthe apparatus will bey apparent tothose `familiar with the art, from an understanding of the foregoingspecification.

I claim:

1. In a machine `of the class described a cylinder, a piston therein, ashaft-extending forward from the piston and carrying a cutting tool, arearward extension from said piston, an opening in the rear end wall ofthe cylinder adaptedto receive the rearward extension and therebyto-trap air behind the piston, Aand a removable sleeve member fitted onsaidrearward extension and adapted to make a close sliding fit in thesaid opening 2. In a machine of the vclass describedfa tool-actuatingmechanism comprising a cylinder, a piston slidable therein, a forwardlyextending shaft attached to the piston andthe piston.

3. In `a machineof the class described,

comprising a cylinder and a tool-carrying piston Vadapted to reciprocatetherein, the n combination of extensions. on` each side of the saidpiston adapted toy fit into vopenings :leading from the respective endsof the `chamber' in which the piston travels,l and removable sleevemembersV surrounding said projections and accurately fitted to slideinto and close the bores forming thesaid openings from the chamber inwhich the piston travels. v

4. In almachine of the class described, a cylinder, a piston therein, ashaft extending forward from the piston and carrying a cutting tool, arearward extension froml said piston, andan opening in the rear end wallof the cylinder adapted to receive'the rearward extension at the end ofthev return' stroke and thereby to trap air between the piston and rearwall to cushion rearward movement of. the piston.

5. Ina machine of the class described, a

tool-actuating mechanism comprising a cylinder, a piston slidabletherein, a forwardly extending shaft attached to the'v piston andcarrying cutting blades, a portion of the said shaft adjacent to thepiston being enlarged, and a detachable collar member securedto theinterior wall of the cylinder and adapted to receive the said enlargedportion ofthe shaftnat the forward end of the stroke of the piston,whereby to trap air between tliefsaid collar member and the piston6 k 4'@i In a machine of the described, the

isa

combination of a cylinder and a ltool-carry- 1 vat each end of thestroke.

V7. In a machine of'the class described, cylinders arranged incooperating pairs, each of said cylinders enclosing a tool-carryingpiston, means to drive Vthe pistonssimultaneously in opposite directionsthe chambers .formed in said cylinders in advance of f the 'said pistonsbeing connected by a passage leadingbetween the two cylinders, wherebyair is driven back and forth lbetween said cylinders.

8.111 a machine of the class described, cylinders arranged incooperating pairs, each of said cylinders enclosing a tool-carryingpiston, the tool being connected thereto by a forwardly extending shaft,said shaft being surrounded rby a fluid-tight bearing "member at theforward end of the cylinder,

a pipe -connecting the chambers in the two cylinders formed between theforward side of their pistons and the said bearing members at theforward ends of the cylinders, whereby fluid pressure may pass from oneof the said chambers to the other' as the-pair vof pistons arereciprocated in opposite directions.

9. '-In a machineof the class described, tool-driving cylinders arrangedin cooperating pairs, each of said cylinders comprising a piston, thetool being connected thereto by an integral forwardly extending shaft,said shaft vbei-ng surrounded by a fiu-id--tivht bearingmember at theforwardend of the cylinder,-an open pipe connectingthe chambers in thetwo cylinders formed between the forward sides of their pistons and thesaid lbearing members at the forward ends of the cylinder's, wherebyfluid pressure may ass from yone of the said chambers to the Lother asthe pistons are reciprocated in opposite directions, and means to 'feed'air into the said pipe from a source of constantly 'maintained fluidpressure.

10. In a machine of the class described, tool-actuating cylindersarranged in v4cooperating pairs, each of said cylinders comprising atool-'carrying piston, thetool being connected thereto by an integralforwardly eX- tending shaft, said shaft being surrounded vby afluid-tight bearing member at the forward end of the cylinder, a pipevconnecting the -chambers in the two cylinders formed. Vbetween theforward side of their pistons and lthe said bearing members at theforward ends of the vcylinders whereby fluid pressure may pass from oneof the said chambers to the other as :the pistons are reciproeated inopposite directions, and a connection leading to the said pipey from asource of lfluid pressure, said connection comprisingV an automaticone-way pressure regulating valve, whereby to maintain a fluid pressurein the two chambers referred to.

l1. In a machine of the class described, the combination of a primarycompression cylinder and a secondary tool-driving cyli-nder, a pipeleading into the said primary compression cylinder, said pipe beingconnected to a source of fluid pressure, a valve in saidfpipe adapted tomaintain a-predetermined minimum pressure in the said compressioncylinder, and means adapted to be moved by the tool` driven by thesecondary lcylinder .whereby to `open the valve to admit 'additionalpressure to the compression chamber when the tool moves backwardpastV apredetermined point. i o

i2., In a machfne of the class described, the combination of a pluralityof primary compression cylinders `and a plurality of secondarytool-driving cylinders, pipes leading into each of the said primarycompression cylinders, said pipes beingconnected to a source of fluidpressure, a valve in each'of said pipes adapted to maintain apredetermined minimum pressure in eaehof the said compressioneylinders,and means actuated by travel of the'tools to open the valves to admitadditional pressure to the compression chambers when the tooly movesbackward past a predetermined point. Y

A13. In a mechanism of the class described, the combination rof aprimary compression cylinder and a secondary tool-actuating cylinder,theltool being carried upon a shaft extending from a pistonreciprocatingin the tool-actuating cylinder, a pipe yleading into thecompression cylinder, said' pipe being connected to a source of fluidpressure through an automatic pressure-regulating valve 'adaptedtomaintain a minimum presv sure in the compression chamber, and meansVractuated by movement of the tool-carrying piston to open said valve toadmit additional pressure to the compression cylinder when the said toolcarrying piston moves backward past a certain predetermined point.

' 14. Ina machine of the class described, 'the combination of a primarydriven piston, a secondary piston driven by' fluid pressure controlledby the first piston', pressure cham-` bers before vand behind thesecondary piston, a source of fluid pressure connected to each of saidchambers, and means actuated ton` a source of fluid Vpressure connectedto `each of said chambers, and automatlemeans piston adapted toreciprocate therein, a connection from the said compression cylinder tothe secondary cylinder, a piston adapted to reciprocate in the secondarycylinder by reason of air pulsations generated thereinto by the pistonof the primary cylinder, a forwardly extendingshaft fixed on the pistonin the secondary cylinder, a cutting tool on the exterior end thereof,an air'passage leading from a source of fluid pressure to J(he primarycompression cylinder, an automatic pressure regulating valve controllingsaid passage and adapted to maintain a minimum pressure therein, aconnecting rod extending from the said valve tothe forward end of thetool actuating cylinder, a support for the .forward endl of 'the saidprod, adjustable means to limit the forward travel of the rod, a springnormally urging the rod forward to its stop position, an extension onthe toolcarrying shaft adapted to contact with the forward end of therod upon the withdrawal of the tool-carrying shaft, an adjustablecontact member betweensaid extension and the end of the rod whereby tovadjust the point of Contact thereof, the rear end of said rod beingadapted to open the said pressure regulating` valve when the rod isforced back.l f j f In testimony whereof, I have hereunto set my hand.

BURT n. onunniuorr.l

